Previous communication systems use techniques that are generally power inefficient. These systems typically employ transmitters and receivers that may require continuous power even during times when they are not transmitting or receiving communications. Such systems that remain idle while still consuming power are typically inefficient from a power perspective.
In some applications, power inefficient communication devices may present limitations as to their continuous use. For example, portable communication devices that rely on battery power generally provide relatively short continuous operation before the battery needs to be replaced or recharged. In some situations, this may result in adverse consequences, such as data loss, communication delays, dropped sessions, and down time.
On the other hand, communication systems that consume substantially lower power during idle times are able to operate for longer periods with a limited power source. Thus, communication systems that power on a transmitter only when the signal is to be transmitted will generally consume less power than a transmitter that is continuously powered. Similarly, communication systems that power on a receiver only when the signal is to be received will generally consume less power than a receiver that is continuously powered.
A pulse modulator may be used to control the times for transmitting and receiving signals. In this regard, a pulse modulator may power on a transmitter local oscillator (LO) for transmitting a signal only for the duration of a pulse. Similarly, a pulse modulator may power on a receiver LO for receiving a signal only for the duration of a pulse. In this capacity, the LO generates and sustains an oscillating signal within the duration of each pulse. If the pulse width is relatively short, such as in a low duty cycle application, the LO should respond quickly to generate a sufficiently stable oscillating signal.